#include <cassert>
#include <csignal>
#include <thread>
#include <atomic>
#include <glib.h>
#include <gst/gst.h>
#include <gst/webrtc/webrtc.h>
#include <gst/app/gstappsink.h>

GST_DEBUG_CATEGORY_STATIC(TEST);
#define GST_CAT_DEFAULT TEST

std::sig_atomic_t got_signal = 0;
static void signal_handler(int)
{
    got_signal = 1;
}

GstElement *create_pipeline(const std::string& file)
{
    GError *error = NULL;
    std::string description = "filesrc location=";
    description.append(file);
    description.append(" ! qtdemux name=d d.video_0 ! h264parse ! mp4mux fragment-duration=1000 ! appsink name=sink drop=false max-buffers=10");
    return gst_parse_launch(description.c_str(), &error);
}

void set_state_blocking(GstElement* e, GstState state)
{
    gst_element_set_state(e, state);
    auto new_state = GST_STATE_NULL;
    while (new_state != state) {
        gst_element_get_state(e, &new_state, nullptr, GST_CLOCK_TIME_NONE);
    }
}

int main(int argc, char *argv[])
{
    std::signal(SIGTERM, signal_handler);
    std::signal(SIGINT, signal_handler);

    if (!gst_init_check(&argc, &argv, NULL)) {
        fprintf(stderr, "FATAL: Failed to initialize gstreamer\n");
        return -1;
    }

    GST_DEBUG_CATEGORY_INIT(TEST, "TEST", 0, NULL);

    GstElement* pipeline = create_pipeline(argv[1]);
    set_state_blocking(GST_ELEMENT(pipeline), GST_STATE_PLAYING);

    std::thread app_thread{[pipeline]() -> void {
        GstElement* appsink = gst_bin_get_by_name(GST_BIN(pipeline), "sink");
        GstSample* video_sample = nullptr;

        // PULL some data first
        for (int i =0 ; i < 100; ++i) {
            video_sample = gst_app_sink_pull_sample(GST_APP_SINK(appsink));
            if (video_sample)
                gst_sample_unref(video_sample);
        }

        GST_ERROR("SEEK");
        if (!gst_element_seek(
            pipeline, 1.0, GST_FORMAT_TIME,
            (GstSeekFlags)(GST_SEEK_FLAG_ACCURATE | GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT), GST_SEEK_TYPE_SET, 10, GST_SEEK_TYPE_NONE, 0)) {
            GST_ERROR("SEEK FAILED");
        }

        GST_ERROR("PULL");
        video_sample = gst_app_sink_pull_sample(GST_APP_SINK(appsink));
        if (video_sample)
            gst_sample_unref(video_sample);
        GST_ERROR("PULL DONE");
        gst_object_unref(appsink);
    }};

    while (got_signal == 0) {
        g_main_context_iteration(nullptr, true);
    }

    set_state_blocking(pipeline, GST_STATE_NULL);
    if (pipeline)
        gst_object_unref(pipeline);
    app_thread.join();
    return 0;
}